Ascorbic Acid Injection
» Ascorbic Acid Injection is a sterile solution, in Water for Injection, of Ascorbic Acid prepared with the aid of Sodium Hydroxide, Sodium Carbonate, or Sodium Bicarbonate. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of ascorbic acid (C6H8O6).
Packaging and storage Preserve in light-resistant, single-dose containers, preferably of Type I or Type II glass.
Labeling In addition to meeting the requirements for Labeling under Injections 1, fused-seal containers of the Injection in concentrations of 250 mg per mL and greater are labeled to indicate that since pressure may develop on long storage, precautions should be taken to wrap the container in a protective covering while it is being opened.
USP Reference standards 11
USP Endotoxin RS
A: To a volume of Injection, equivalent to 40 mg of ascorbic acid, add 4 mL of 0.1 N hydrochloric acid, then add 4 drops of methylene blue TS, and warm to 40: the deep blue color becomes appreciably lighter or is completely discharged within 3 minutes.
B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that of the Standard preparation, obtained as directed in the Assay.
C: It responds to the flame test for Sodium 191.
Bacterial endotoxins 85 It contains not more than 1.2 USP Endotoxin Units per mg of ascorbic acid.
pH 791: between 5.5 and 7.0.
Limit of oxalate Dilute a volume of Injection, equivalent to 50 mg of ascorbic acid, with water to 5 mL. Add 0.2 mL of acetic acid and 0.5 mL of calcium chloride TS: no turbidity is produced in 1 minute.
Other requirements It meets the requirements under Injections 1.
Mobile phase Dissolve 15.6 g of dibasic sodium phosphate and 12.2 g of monobasic potassium phosphate in 2000 mL of water, adjust with phosphoric acid to a pH of 2.5 ± 0.05. Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation Dissolve an accurately weighed quantity of USP Ascorbic Acid RS in Mobile phase, and mix to obtain a solution having a known concentration of about 0.5 mg per mL. [noteRefrigerate and store protected from light until use. The solution is stable for at least 24 hours. Inject within 3 hours after removal from the refrigerator. ]
Assay preparation Dilute the Injection, quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a concentration of about 0.5 mg per mL. [noteRefrigerate and store protected from light until use. The solution is stable for at least 24 hours. Inject within 3 hours after removal from the refrigerator. ]
Chromatographic system (see Chromatography 621)The liquid chromatograph is equipped with a 245-nm detector and a 6-mm × 150-mm column that contains packing L39. The flow rate is about 0.6 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the column efficiency is not less than 3500 theoretical plates, the tailing factor is not more than 1.6, and the relative standard deviation for replicate injections is not more than 1.5%.
Procedure Separately inject equal volumes (about 4 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peak. Calculate the quantity, in mg, of ascorbic acid (C6H8O6) in each mL of the Injection taken by the formula:
CD(rU / rS)in which C is the concentration, in mg per mL, of USP Ascorbic Acid RS in the Standard preparation; D is the dilution factor; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2242